用于光生毫米波的双频微片激光器热致频差特性研究

研究了激光二极管端面抽运的双纵模双频微片激光器的热效应对其输出频谱的影响. 通过对端面抽运Nd:YVO₄微片的热传导方程求解得出晶体内部的温度场分布; 并进一步对微片晶体热致折射率变化进行分析, 由此计算出双频微片激光器的热致频谱变化. 实验结果表明: 当抽运功率较小时得到稳定的双纵模双频激光输出; 当抽运功率增大时, 晶体热效应使双频激光频谱双峰之间的频差减小, 各纵模波长频谱宽度加宽, 实验结果与理论分析相符合. 关键词： 光载无线通信 双频微片激光器 热效应 频率差

Thermally induced frequency difference characteristics of dual-frequency microchip laser used optical generation millimeter-wave

The thermal effect of laser diode end-pumped double longitudinal mode dual-frequency microchip laser on dual-frequency laser spectrum is investigated in detail. Through solving the heat conduction equation of isotropic material, a general expression of temperature field within Nd:YVO₄ microchip crystal is obtained, then the thermally induced refractive index change of microchip laser is analyzed, and thus the thermally induced frequency difference change of dual-frequency microchip laser is calculated. According to the theoretical results, an experiment is designed. The experimental results show that with a small pumping power, astable doublelongitudinal mode dual-frequency is obtained; increasing the pumping power, the thermal effect of crystal makes the frequencydifference decrease gradually, and the width of each mode spectrum broaden. The experimental results are in good agreement with the theoretical analyses.
Keywords： radio over fiber dual-frequency microchip laser thermal effects frequency difference